Bicycles were originally developed to increase the speed and ease of progressing over the surface of the Earth. All land animals are able to progress over the surface of the Earth by the use of either legs or by the use of undulations such as used by snakes, snails, and the like. Some snakes are able to progress at a remarkable rate which, however, is nowhere near as rapid as many life forms and particularly mammals and reptiles are able to attain by the use of legs. The use of legs, however, requires considerable energy for activation of the back and forth motion of such legs. Each forward propelling motion made by a leg requires a corresponding reversal of motion to retain a position wherein the leg can again propel the animal forward over the surface. Furthermore, with a decreasing number of legs the motion of the organism over the ground becomes more and more undulating. Thus an insect with six legs may run almost level, a four legged mammal with accelerated movement will demonstrate more up and down motion and a two legged mammal, bird, or reptile will demonstrate still more up and down or vertical movement associated with forward motion, since the “gate,” or leg facilitated motion, of the organism is basically a matter of lifting the body to its maximum standing height and then allowing the body to fall or pivot forward and down before being caught by at least one leg before sinking too low for such leg to raise the body up again and enable it to be carried forward either by the other paired leg or in a four footed animal often by the pair of legs behind. Energy is saved by having to move fewer legs as one progresses to a two-legged stride. However, having to catch the body as it falls forward and downward and lift it up again for every stride also takes significant extra energy. The advantage of having fewer legs thus ultimately is used up in continuously lifting the body upwardly. Legs also have an advantage in progressing over rough ground, provided an effective sight and obstacle avoidance system is incorporated into the animal as part of its onboard computer or computer guidance system, or brain. Humans, or homosapiens, discovered, or realized, somewhere on the Eurasian landmass more than five millennia ago that a round section of a tree trunk can roll along a smooth surface with a minimum of dissipated energy. This led after a time to simple two wheeled carts and then chariots. Strangely, the wheel concept was never discovered by the indigenous peoples of the new world, Australia and the Pacific Basin. However, in Eurasia, where it was, the necessity for cleared paths or roads which could accommodate wheeled vehicles drawn by animal or human power become gradually evident. Once sufficient reasonably constructed or smooth roads became available, furthermore, the use of on board power for vehicles became possible. On board power was provided either by internal combustion engines or external combustion or steam engines or in the case of the bicycle, human muscle power. A wheeled vehicle on a reasonably smooth surface does not require significant power to lift the vehicle plus any passengers upwardly with every step, thus saving a very considerable amount of energy as it progresses along the road. Such saved or preserved energy or excess energy can then be used in accelerating forward movement of the vehicle. With the invention of the bicycle, the decrease of energy necessary for maintaining horizontal movement of the vehicle made it practical to progress over the surface of the ground either with the expenditure of much less energy than necessary for walking or even running or, with the exertion of the same energy, to go very considerably faster. Initially, bicycles utilized a large wheel propelled or rotated directly by pedals attached to central portions of the drive wheel or alternatively to the shaft upon which the drive wheel was mounted, thus gaining a mechanical advantage which allowed the bicycle to attain speeds unobtainable by foot. Bicycles were initially, therefore, mechanical devices developed to travel faster over smooth surfaces than is possible by foot, or capable of traveling at similar speeds as attainable on foot but with the expenditure of significantly less energy. Bicycles were thus initially devices for moving across the ground at a faster speed using a lesser amount of energy than was possible on foot. It is strange in view of this original genesis of bicycles that modern bicycling has developed into a form of exercise using a lesser amount of energy, no doubt a major reason why it is popular as an exercise medium, since a bicycle can be characterized as a mechanical device for obtaining exercise with the expenditure of less energy or less exercise. Those who like bicycling and want to use more energy can, of course, increase their speed until they are in fact using more energy rather than less than they would for mere walking or even fairly leisurely jogging or running.
The use of a rotating wheel in bicycles and other wheeled vehicles not only saves energy by eliminating the up and down motion characteristic of progression over a surface by means of legs, at least assuming the absence of potholes, but also by maintaining the movement of the wheel progressing over the surface in a single direction without periodic reversals of movement. Not only is the forward momentum of the body maintained, but the motion or momentum of the wheel itself is maintained in a single direction about its axis so it maintains at least a single rotational momentum or angular momentum, although not a completely uniform momentum with respect to the vehicle. A wheel, however, does avoid periodic complete reversal of motion. The continuous angular change of motion of the rim of the wheel as it rotates about the axis of the wheel, while using excess energy, is nowhere near as wasteful of energy as complete reversal of motion as found in the movement of legs progressing in a back and forth motion.
It is a remarkable fact that nature in the form of land animals has never developed through evolution any organ operating in the same manner as a wheel, probably due to the technical problems of passing blood vessels or nerves successfully past an axis of rotation, although some insects attain a similar semi-rotary motion of their wings and some fish come close to rotary motion of their pectoral fins, not directly about an axis, but at a lateral angle about what is in effect at least a semi-axis.
Since the advantages of the gearing principle applicable to effecting bicycle movement was evident from the first and the disadvantages of having the mechanical advantage means positioned on the wheel used for steering became quickly evident, it was not long before the mechanically minded began applying the pedal mediated power in bicycles to a rear wheels through a chain drive device or similar arrangement, the mechanical advantage being obtained by using a relatively small sprocket in conjunction with the pedals and a still smaller sprocket in conjunction with the large drive wheel. The use of additional sprockets to obtain additional mechanical advantage quickly followed and various gear changing arrangements began to be used after the Second World War. At first, these allowed one to change the gear ratio only on the rear sprocket, using gear levers on the handle bar. This has now resulted in the use of several gear changing mechanisms, usually in the form of a so-called derailleur which biases a drive chain to the side from one gear sprocket to another gear sprocket alongside. While at one time it was necessary to either stop the bicycle or at least slow such bicycle drastically to change the gear mechanism, modern derailleurs do not require such slowing of movement, but are enabled to shift smoothly while moving and in fact frequently require one to be peddling at the time the gear ratio is changed by shifting the sprocket chain from one sprocket gear to another. It is this type of gear changer, or derailleur, that is used in conjunction with the present inventor's high speed bicycle system.
While bicycles therefore were originally developed to enable users thereof to travel along roads, pavements and streets at a faster rate and with the expenditure of less energy than is possible on foot, either by walking or running, by the judicious or effective use of favorable gear ratios, it has not been possible for the average rider to effectively attain really elevated or rapid speeds. While bicycles have been developed with multiple extended gear ratios to either attain rapid movement with the expenditure of minimum or very reduced energy and gear changing arrangements, frequently referred to as derailleurs, principally so that lower gear ratios can be used when ascending grades of various pitches or inclinations, and while specialized high speed bikes for racing have been designed, there has been no effective high speed bike for mass or everyday use. When derailleurs, which enable the gear ratio of the drive chain of a bicycle to be altered by the shifting the drive chain from one size sprocket to another and thereby allowing the effective leverage or gear ratio applied to the drive wheel by the muscles of the legs of the bicyclist to be effectively changed by changing the size of the sprocket the chain revolves around, the derailleur had at first to be operated either while the bike was stationary or moving relatively slowly. This required the bike to be essentially stopped when it was desired to change the gear ratio. This limited the gear changing to adjusting essentially to major changes in inclination of the landscape. More modern derailleurs, however, can now change the position of the drive chain from one sprocket wheel to another while the bicycle is moving and, in fact, frequently require movement of the sprockets in order to effect efficient change from one gear to another. Bicycles have, as a result, become even more practical for both personal transportation and for sport or exercise by those who enjoy traveling over the terrain at relatively elevated speeds compared to the speed which could be attained with the same amount of energy expenditure on foot. Nevertheless, while bicycles have become very efficient, practical mass transportation devices, high-speed bikes have not been available. Carefully analyzing this anomaly, the present inventor has realized that the problem lies in the relative relationship or interrelationship of changing gear ratios, the accompanying momentum of the bicycle and rider at the time of gear changing and the relative high gear ratios necessary to drive a bicycle at high speeds combined with the relative restricted maximum rapidity of movement of the legs of the usual rider. While professional or even amateur bicycle racers with powerful well trained and conditioned legs are able to and, in fact, revel in moving their legs rapidly about the pedals of a bike, thereby attaining very rapid velocities, the normal, or average, rider does not have such well trained legs and can neither attain the leg thrust or power nor the rapidity of leg movement that a well conditioned bicycle racer can. As a result, the normal everyday rider reasonably enough requires more effective gear ratios to attain high speeds. In other words, the gear ratio of the bike must be such that the average rider moving the pedals at a reasonable rate and with a comfortable or easily attainable force will be able to attain a high speed. However, the problem is that with the high gear ratios necessary to achieve high speeds any impediment to forward movement such as a slight grade, a slight opposite wind or the like will cause a relative high retarding force, such force being immediately applied with very little mitigation to the legs of the rider. At high speeds, in addition, the momentum of the rider and bike becomes quite pronounced. As long as such momentum is maintained, driving or propelling the bike either at a constant speed or at a slowly but steadily increasing speed is not a great problem. However, if a slight upward incline or a slight headwind retards the rider, the accompanying loss in momentum may have a disastrous effect upon the power speed relationship.
In order to compensate for the large interrelated effects of grade, headwinds and inherent momentum at the high gear ratios sustainable by the average riders the present inventor has realized that it is necessary to have as many easily changeable gears as necessary to maintain a smooth speed of the bike with minimum hesitations or changes in speed or momentum. This aim is attained by having at least four sets of gears each with their own gear changer with a predetermined sequence of gear changing from lowest to highest, so that the speed and momentum of the bicycle can be easily attained in the first place and then maintained whatever the conditions. This requires the addition of at least one extra gear shaft and two sets of associated sprocket gears to the usual bicycle. More particularly an auxiliary gear shaft having at lest four small diameter gear sprockets on a single shaft plus at least three large gear sprockets on the same shaft is used to mediate power from the pedal sprockets to the drive sprockets of the bicycle.
Furthermore, since for maximum efficiency of the derailleurs it is desirable for the sprockets at both ends of a sprocket chain to be as far as conveniently possible from each other to decrease the angle of change of the chain between adjacent sprocket wheels or gears, it has been found that the most efficient placement of the extra sprocket wheel shaft and associated sprocket wheels will be within the frame of the bicycle just under or below the seat and toward the rear of the bike. This provides a strong well-positioned location where the sprockets are held rigidly in place, but spaced a reasonable distance from the sprockets on the drive wheel shaft and the sprockets on pedal shaft. Preferably this extra sprocket shaft with its two sets of auxiliary sprockets is mounted securely between two separate frame pieces of the bike frame. Two separate derailleurs are provided to change two separate sprocket chains between the various sprockets of each set of auxiliary sprocket wheels.
The present inventor has realized, therefore, that if carefully calculated and coordinated sets of gearing are provided on a bicycle including (a) a set of gears with a derailleur on the pedal cassette, or set of sprocket wheels, to change the bicycle chain from one sprocket to the other, (b) a set of gears on the drive wheel assembly in the form of a cassette, or set of sprocket wheels on the drive wheel with a derailleur to change the chains from one to the other and two sets of sprocket wheels or separate cassettes of gears on an auxiliary gear axle mounted on the center line of the bicycle close to the seat and toward the back of the bicycle and usually somewhat under and in back of the seat, each set of sprocket wheels or cassettes being supplied with their own derailleur, or gear changer, a very smooth operating bicycle with a very high top speed can be obtained. The principle embodied is that sufficient gears or sprocket wheels must be provided so that particularly at high speeds very smooth changing from one gear ratio to another must be available. The inventor has calculated that sufficient gear changing or derailleurs must be available so that not more than 5 foot pounds of force is necessary to maintain and increase speed at any point of the changing speed. More particularly the gearing should be such that only a single push or depression of the pedal is necessary to effect the next change in speed. With the illustrated arrangement this relative speed and power relationship is easily attained such that speeds of well over 120 miles per hour and up to 160 miles per hour are easily attained, although for safety reasons the rider will usually ride at lesser speeds. Furthermore, additional gear cassettes may be used to attain even higher speeds, which however, because of safety considerations may not be desirable. Once such elevated speeds are reached, preferably a set of gears will be used for careful maintenance of velocity and therefore momentum in which the individual sprockets of the set are relatively close together or matched in size so that relatively small adjustments in speed can be attained with relatively small changes in gear ratios.
The inventor is aware of the following prior art patents showing multiple gear bicycle systems and multiple derailleur or gearshifting mechanisms, but none of such systems disclose the present applicant's system.
U.S. Pat. No. 490,252 issued to A. D. Jenkins on Jan. 17, 1893, entitled “BICYCLE,” discloses a bicycle having a pair of small sprocket wheels on the rear wheel, a pedal having a double sprocket arrangement, and one small, intermediate and inordinately large sprocket wheel situated on the bike frame generally in front of the pedal area. Jenkins is one of the earliest references disclosing a bike gear arrangement including more than two sprocket wheels situated to increase the speed of the cycle.
U.S. Pat. No. 520,796 issued to C. R. Mayne on Jun. 5, 1894, entitled “BICYCLE,” discloses a cycle wherein the front and rear wheels have an inner rim on which “planet wheels” are made to circulate about a central axis. In FIG. 4, a pedal sprocket is secured to rear wheel sprocket by a chain, while a planet wheel is also geared to a further sprocket adjacent to the rear sprocket by a belt via a smaller wheel. While Mayne indicates that this is a form of speed gearing, exactly how such arrangement works is not immediately clear.
U.S. Pat. No. 559,299 issued to C. O. E. Matthern on Apr. 28, 1896, entitled “BICYCLE,” discloses a two-wheeled velocipede having an intermediate sprocket or gear situated slightly behind and below the seat of the cycle. As shown in FIG. 2, the frame of the cycle has been adapted to hold such sprocket. As shown in FIG. 1, a chain extends between a pedal sprocket wheel and an upper sprocket, while a second chain extends between larger upper sprocket and a rear wheel sprocket. Matthern also provides that the pedal sprocket wheel can be driven directly on second rear wheel sprocket when normal pedaling speeds are desired.
U.S. Pat. No. 641,980 issued to W. W. Lower on Jan. 23, 1900, entitled “HIGH SPEED GEAR FOR BICYCLES,” discloses another cycle having an intermediate gear arrangement. The Lower gear arrangement is different from the Matthern arrangement discussed above in that the intermediate sprocket is situated more or less directly above the pedal sprocket, rather than behind the rear seat.
U.S. Pat. No. 789,580 issued to W. Trainor on May 9, 1905, entitled “DRIVING GEAR FOR CYCLES,” discloses an intermediate gear having sprockets which are essentially clamped to the downwardly extending frame member of the cycle. Trainor is directed to another means for attaching an intermediate sprocket to a bicycle.
U.S. Pat. No. 1,154,292 issued to T. J. Cribbs on Sep. 21, 1915, entitled “BICYCLE TRANSMISSION,” discloses another intermediate gear or sprocket arrangement which extends upwardly from the standard gear sprocket and includes a smaller and larger sprocket wheel. Cribbs is unique in that the intermediate sprockets are secured to both the downwardly extending frame member and the horizontal frame member of the cycle. In addition, the Cribbs gear system apparently can be attached to a standard bicycle, thereby increasing the speed of such cycle.
U.S. Pat. No. 1,360,032 issued to E. and J. Schiffner on Nov. 23, 1920, entitled “BICYCLE GEARING,” discloses an improved bicycle arrangement comprising an intermediate gearing connection between the pedal crankshaft and rear wheel of a bicycle so that the speed of the bike is increased for each given rotation of the pedal crankshaft without enlarging the sprocket wheel of such crankshaft. The Schiffner intermediate gearing connection includes a small and larger sprocket wheel so that a chain connects a pedal sprocket with the small sprocket wheel and chain connect the larger intermediate sprocket with the rear wheel sprocket. The speed of the rear wheel is therefore increased with each turn of the pedal crankshaft.
U.S. Pat. No. 1,380,082 issued to J. C. R. Schleder on May 31, 1921, entitled “BICYCLE,” discloses another intermediate sprocket or gear arrangement which, as shown in FIG. 6, is clamped to the frame of the cycle in a slightly different manner. In Schleder, the intermediate gear is disposed nearer the rear wheel of the cycle, rather than directly above the pedal crankshaft or under the seat as in previous disclosures.
U.S. Pat. No. 1,535,714 issued to L. F. Burke on Apr. 28, 1925, entitled “BICYCLE GEARING,” discloses a gear combination between the pedal shaft and the rear wheel. As indicated in column 1, lines 15–20, this is so that “the gear ratio of the bicycle can be increased without increasing the size of the crank shaft sprocket and thus decreasing the crank leverage.” In addition, lines 39–40 of column 1 state “It has been suggested to use a double set of sprockets and two chains.” Referring to FIG. 1, bike frame (10) includes two crankshafts, with the first crankshaft having pedals and large sprocket thereon. Second crankshaft includes a small sprocket and a larger sprocket. The rear wheel of the bike also includes a small sprocket. Chain connects pedal sprocket with small sprocket, while chain connects sprocket (15) with rear wheel sprocket. Apparently, bike frame diagonal member may be pivotable at a point just below the seat. In addition, a horizontal member is apparently adjustable so that the tightness of one of the chains can be adjusted without the other chain becoming loosened as in prior art arrangements.
U.S. Pat. No. 1,630,442 issued to G. Makris on May 31, 1927, entitled “BICYCLE,” discloses a bicycle having two, rather than one, intermediate sprocket wheels. Makris essentially uses two rather than one intermediate so that the speed of the bicycle is increased a further multiple which is dependent upon the exact gear ratios of the sprockets.
U.S. Pat. No. 3,921,467 issued to H. Matsuura on Nov. 25, 1975, entitled “DRIVE SYSTEM FOR CYCLE,” discloses another gearing system which includes an intermediate sprocket arrangement. Primary sprocket includes pedals on crankshafts, while rear sprocket is secured to the rear wheel of the cycle. Intermediate sprockets are situated so that primary chain extends between primary sprocket and smaller intermediate sprocket, while second chain extends between larger intermediate sprocket and rear sprocket. Matsuura generally teaches the use of a secondary or intermediate sprocket or gear system to increase the speed of the bike. The main inventive feature of Matsuura appears to be the addition of tensioner sprockets which are used to guide or position primary chain.
U.S. Pat. No. 4,173,154 issued to N. E. Sawmiller et al. on Nov. 6, 1979, entitled “BICYCLE DRIVE SPROCKET SYSTEM,” discloses an alternative pedal drive arrangement wherein the pedal sprocket is actually comprised of a pair of sprockets secured together by a chain. Such combination is used to give the pedals an oval pedal path, which Sawmiller claims increases the power and speed of the cycle. Sawmiller therefore does not actually disclose an intermediate sprocket, but a pair of sprockets comprising the pedal sprocket, rather than the standard single crankshaft and sprocket.
U.S. Pat. No. 4,502,705 issued to J. B. Weaver on Mar. 5, 1985, entitled “SEMIRECUMBENT TANDEM BICYCLE,” discloses another cycle arrangement which utilizes several chains and gears or sprockets to apparently increase the speed of the cycle. The position of the front pedal sprocket and crankshaft can be changed, as shown in FIG. 1. However, the cycle can also be pedaled using standard crankshaft, so that the cycle can be ridden in either an upright or semi-recumbent position.
U.S. Pat. No. 4,826,191 issued to D. A. Matre et al. on May 2, 1989, entitled “BICYCLE OR TRICYCLE,” discloses a bike wherein the position of the pedal sprocket is adjustable. As shown in FIG. 2, the bike includes second, third, and fourth sprockets. The second sprocket connected and positioned near the pedal sprocket, the third sprocket is positioned adjacent the second sprocket, and the fourth sprocket is on the rear wheel. In the disclosed gear system the intermediate sprockets are preferably the same size, with the main purpose of the invention appearing to be the adjustability of the pedal sprocket rather than producing faster speeds. However, lines 53–56 of column 2 indicate that the rotational speed of the rear wheel can be modified by “replacing the sprocket [the third sprocket] with one having a different size.
U.S. Pat. No. 5,102,155 issued to T. Chou on Apr. 7, 1992, entitled “BICYCLE WITH TWO SPEED-CHANGING MECHANISMS,” discloses another intermediate sprocket system for increasing the speed of a bicycle. Chou includes both a small and large intermediate sprocket. Of note is the fact that the smaller intermediate sprocket has a smaller radius than the pedal sprocket, while the larger intermediate sprocket has a larger radius than the pedal sprocket. A bracket is also provided in the frame of the bike for holding the intermediate sprocket system just behind the pedal sprocket and crankshaft.
U.S. Pat. No. 5,209,507 issued to A. Domenge on May 11, 1993, entitled “TRANSMISSION SYSTEM FOR TANDEM BICYCLES,” discloses, as best shown in FIG. 2, a transmission or gear system having an intermediate gear with a larger and smaller sprocket thereon. The Domenge system includes an intermediate sprocket with a crankshaft and pedals so that two persons can ride and pedal the bike at the same time. FIG. 12 discloses another embodiment wherein a third seat and crankshaft is added behind the rear wheel.
U.S. Pat. No. 5,577,749 issued to T. Ross on Nov. 26, 1996, entitled “TWIN GEAR DRIVE ASSEMBLY FOR A BICYCLE,” discloses another bicycle having a third or intermediate gear assembly for increasing the speed of the cycle without increasing the effort required by the user.
U.S. Pat. No. 5,913,741 issued to J. P. Balajadia on Jun. 22, 1999, entitled “BICYCLE WITH THREE BOTTOM BRACKET SHELLS AND GEARING SYSTEM,” discloses, as shown in FIG. 8, a bike frame having a pair of intermediate gear arrangements each having one larger and one smaller chain sprocket thereon. Three chains are utilized in the Balajadia system, rather than two.
U.S. Pat. No. 5,979,924 issued to C. P. D'Aluisio on Nov. 9, 1999, entitled “CRANK ASSEMBLY FOR A BICYCLE,” discloses, as shown in the FIGS., a plurality of intermediate sprockets each having separate chains which are generally situated around the pedal crankshaft area of the bike. 0′ Aluisio is an example of the current state of the art in cycle having a plurality of sprockets so that the overall wheel speed of the cycle is significantly increased. 0′ Aluisio also includes a good discussion of the theory behind such speed increase in the “Background” section, as well as several charts in columns 10–12 discussing the differences between various gear sizes. The 0′ Aluisio system is also designed for use on a mountain bike having a full-suspension, rather than a road bike.
U.S. Pat. No. 6,347,803 issued to O. L. Berges on Feb. 19, 2002, entitled “BICYCLE WITH TWO CHAIN DRIVEN DIFFERENTIALS” discloses another state of the art bike transmission or gear system having more than the standard pedal and rear tire sprocket arrangement.
None of the above cited references disclose or suggest the arrangement of the present inventor therefore provides a system by the use of which a very high speed may be attained on a bicycle with minimum effort.